Flame retardant, phosphorus-containing polymers are well-known in the industry. These polymers are used to impart a degree of flame resistance to cellulose-containing fabrics, such as cotton fabrics. The polymers typically are produced by padding a tetrahydroxymethyl phosphonium compound and a suitable cross-linking agent onto the fabric and reacting the two to form the polymer. The polymers produced by this reaction are known to release formaldehyde overtime, which can be problematic for a variety of reasons. The industry has attempted to develop means to solve this formaldehyde generation problem, but these means seldom provide a long term solution. Indeed, many of the solutions lose their efficacy after the treated fabric is washed only a couple of times and the polymer on the fabric then begins to release formaldehyde.
A need therefore remains for improved flame retardant, phosphorus-containing polymers that generate reduced amounts of formaldehyde. A need also remains for processes for producing such polymers and articles treated with such polymers. The invention described in this application aims to satisfy such need.